Drying apparatus



March 18, 1930. HQPKINSON 1,750,753

DRYING APPARATUS Filed April 10; 1926 2 Sheets-Sheet 1 FL La 13 INVENTOR. 2772a; flap/imam.

March 18, 1930. E. HOPKINSON DRYING APPARATUS Filed April 10, 1926 2Sheets-Sheet 2 I a a A E B i 10 m I: g

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deposit to form crude rub has many advanta es such as speed, econPatented Mar. 18, 1930 UNITED STATES PATENT OFFICE mums! HOPKINSON, OFNEW YORK, N. Y., ASSIGNOR '10 GENERAL RUBBER COMPANY, OF NEW YORK, N.'Y., A CORPORATION OF NEW JERSEY DRYING APPARATUS Application filedApril 10, 1926. Serial No. 101,060.

This invention relates to a drying apparatus, more particularly to anapparatus for spra drying rubber latex, and other materia s.

In recent years there has been an extensive development of theproduction of'crude rubber by drying rubber latex in comminuted formwhile suspended in a current of heated drying medium, and com ressingthe dried her. This method omy, production 0 a uniform rubber, andretention of all the solid constituents of the latex in the rubber, andthe material thus produced also is of superior strength and vulcanizinqualities. Patents have been taken out or spray drying'the rubber latex,but the apparatus is more particularly designed for use on' alargescale.

An object of the resent invention is to provide a simple, efficient andinexpensive ap aratus for spray drying rubber latex.'

other object is to provlde an efficient and easily varied means fordistributing the drying medium in the drying chamber.

A further object is to provide a simple, easily cleaned and efiicientcollecting device for treatment of the exhaust gases.

The inventionaims in general to produce a small, compact and easilyassembled latex drying apparatus particularly adapted for use on smallplantations.

Without intention to limit the invention otherwise than as is requiredby the prior art, the same consists'broadly in achamber of circular orapproximately circular form, provided with a spraying apparatuscentrally disposed therein near the top, variable means for supplying adistributed and downwardly directed current of drying medium at the topof the chamber, with means for preventing direct access of said dryingmedium made to the accompanyingspecification and drawings, in whichlatter Fig. l is a side elevation of the drying apparatus; o a

Fig. 2 is a horizontal section on the line 2 2 of Fig. 1; and

Fig. 3 is a vertical section on the line 3-3 of 2.

Re erring to the drawin s, the numeral 1 designates generally the ryingapparatus, the walls of which may be heat insulated in any suitablemanner as shown at 2. This apparatus may be of circular or approximatelycircular "form. The interior of the drier 1 is divided into a dryingchamber 3 and an air supply and distributm chamber 4 by means of thepartition 5. In t e present instance the partition is formed of metallicgauze, but it is obvious that a perforated sheet may be used instead.Leading into the distributing chamber 4 is a, supply pipe 6 which isconnected to a furnace 7 for supplying the drying medium, such as amixture of heated air and combustion products, and in order to morewidely distribute the drying gas in the chamber 4, a curved perforatedbafll'e 8 is disposed in front of the outlet from the pipe 6. Dependingfrom the center of the top of the drier is a heat insulated casing 9preferabl of cylindrical form, this casing extending ownwardly to thegauze 5 and providin a cylindrical opening in which is d1s osed t esprayer unit 10. This unit may e of any suitable form, but is preferablyof the centrifugal type and is rovided with a rotating sprayer disc 11to which the latex, or other material to be dried, is supplied. In thepresent instance it is shown as a self-contained electrically driven onesuch as that shown in patent to C0flin, No. i 90 1,558,593, October 27,1925, with the exce tion that the spray disc is slightly dished.

Thespr-ay unit is furnished with any suitable connections for latex andwatensu plies, which are preferably carried in tanEs 10' and 10? on thetopof the drying apparatus, and the method of operation is as describedin said patent. i

In order to properly distribute the drying medium in the chamber,bafiles are provided which may rest directly upon the gauze 5. It isessential that a direct flow of the drying air to the side wall of thedrying chamber be prevented, and to accomplish this a bafile 12 may beplaced upon the gauze 5 next to the side wall of the drier 1. Thisbafiie may be formed of any desired number of pieces and it is notlimited in size to the relative proportions shownin the drawings, aslong as it extends inwardly from the side wall a suflicient distance toprevent the downwardly flowing current of drying medium from directlystriking the side wall. It is also desirable to prevent direct access ofthe drying medium to the latex flowing outwardly on the disc 11, and toaccomplish this result a bafiie 13 is disposed upon the gauze 5 aroundthe insulated casing 9. The opening through the gauze 5 between thebafiles 12 and 13 may be partially closed off in any desired manner todistribute the downwardly flowing current of drying medium as required;In the present instance an intermediate bafile ring 14 is shown, whichring may be, formed of sections of any suitable size.

Ad acent the bottom of the drying chamher a series of exhaust openingsor outlets 15 is provided, which outlets are preferably symmetricallydisposed around the chamber and are suflicient in number and extent toprovide a large aggregate exhaust area. Communicating with each opening15 is an exhaust box or collector 16 in the form of a casin secured tothe outer wall of the drying chamber and closed at the bottom and o n atthe top. Extending across the intenor of each casing are the staggeredb'aflles 17, and in order to provide for the easy removal of depositsfrom the casing, a door 18 is disposed in its outer wall. To rovide forthe removal of the dry deposit from the floor the drying chamber, one ormore of the casings 16, instead of being fixedly con nected to the wallof the drying chamber, may be hingedly connected as shown at 19in Fig. 1In this case, an opening 20 is cut in the wall of the drying c amber toform a doorway, and the casin 16 is provided with an inner wall20'.cover1n the doorway, the wall 20' being formed adjacent its bottompor ion with an exhaust opening 15' corre-- nding to the openings 15.One or more of t e doors 18 may be also provided with a small slidewa 21(Fig.1) through which samples may e'taken when desired without openingthe entire door. Pee holes 22 are alsoprovided in the side wa of thedrier and a light 23 may be dis (1 opposite one of these holes foruminatmg the interior of 5?: tier. 1A stairwa 24 is provided for readyaccess to the top 0 the drier.

- In operationthe'furnace is started, and

after the drying medium is being supplied at the proper temperature, itis diverted through pipe 6 into the supply chamber at the top of thedrier, and an even distribution in this chamber is secured b means ofthe curved perforated baflle 8. he sprayer 10 having been started, thelatex is thrown oil from the disc 11 in .an umbrella shaped spray, andby properly proportioning the disc and the diameter and height of thedrying chamber and regulating the speed of the disc, this spraywill notcontact with the side wall of the drying chamber but will closelyapproach it adjacent the bottom. By reason of the bafile 12, thedownwardly directed current of drying medium cannot directly strike theside wall of the drying chamber but impinges on the expanding anddescending spray of latex. The bafile 13 prevents direct contact of thedrying medium with the spraying disc so that the current of drying airdoes not strike the sprayed latex until shortly after it has left thespraying disc. By varying the size and arrangement of the intermediatebaffle 14 any suitable distribution of the drying medium may beobtained. By properly regulating the temperature and speed of the dryinggases and properly proportioning the number and size of the exhaustoutlets 15, almost the entire quantity of dried material will depositeon the bottom of the drying chamber. As the exhaust gases flow outwardlythrough the openings 15 and casings 16, the staggered bafiles 17 causethe gases to pursue a tortuous upward path before exhausting from thetop of the casings 16, and 'as a result there is a very efiicientrecovery of an fine dried particles which have not deposited on thebottom of the drying chamber. \Vhen it is desired to remove accumulateddeposits from the exhaust boxes or casings 16, this can readily be doneby opening the doors 18 in the casings. When a sufiieient quantit ofdried material has accumulated on the oor of the drying chamber the oneor more casings 16 which are hingedly mounted, may be opened and theoperatives may then remove the deposit of dried latex through thedoorway 20. This spongy deposit, which resembles fine textured spongecake in appearance, may then be placed in a press and compacted to formcrude rubber. By my invention there has been provided a small, compact,easily assembled, economically and easily operated drying apparatus,which is particularly suited for use on small plantations where thequantity of latex is insufiicient to permit the use of a large dryingapparatuswhich ordinarily is most economically operated when runcontinuously.

\Vith the above detailed disclosure in mind, it is obvious thatnumerousmodifications will suggest themselves to those skilled in theart and it is not desired to limit the invention other'wisethan assetforth in the appended claims.

Having thus described my invention, what I claim and desire to protectby Letters Patent is 1. In an apparatus for drying latex and similarmaterial, a dryin chamber, a disk sprayer centrally dispose adjacent thetop thereof, a su ply chamber for a drying medium above t e dryingchamber, a perforate screen separating the chambers, im erforate meansdisposed on said screen to efine an annular opening adjacent but offsetfrom said sprayer and a second annular opening of greater diameterspaced from the side wall, and equidistant exhaust openingsof largeaggregate area in the side wall adjacent the bottom of the dryingchamber.

2. In an apparatus for dr ing latex and similar material, a dryin camber, a disk sprayer centrall dispose adjacent the top thereof, meansor supplying spaced downwardly directed currents of drying medium inannular form at points adjacent the sprayer and spaced from the sidewall of the chamber, a plurality of equidistant exhaust openings in theside wall adjacent the bottom of the chamber, and exhaust boxes disposedaround the outside of the drying chamber and communicating with saidopenings, one of said boxes being hingedly mounted and forming a doorwayto the drying chamber.

3. In an apparatus for drying latex and similar material, a circulardrying chamber, a supply chamber for a drying medium above the same, aperforate screen between the two, a disk sprayer centrally located inthe upper part of the drying chamber, imperforate means of annulariormdisposed on said screen next to the side wall, additionalimperforate annular means "disposed on the screen in spaced relation tosaid first annular means, and a plurality of equidistant exhaustopenings of large aggregate area disposed in the side wall at the bottomof the chamber.

said well to the wall and defining an upper drying medium supply chamberand a lower drying chamber, means on said screen'for preventing directaccess of the drying medium from the supply chamber to the wall at theupper portion of the drying chamber, means for preventing direct accessof the drying medium to the spraying disc, and exhaust meiilns adjacentthe bottom of the enclosing wa Signed at New York city, county of NewYork, and State of New York, this 29th day of March, 1926.

ERNEST HOPKINSON.

4. In an apparatus for drying latex and similar material, a circulardrying chamber,

the same, a perforate screen between the two, a disk sprayer centrallylocated in the upper part of the drying chamber imperforate meansdisposed on said screen for preventing direct access of the dryingmedium to the surface of the disk, imperforate means disposed on saidscreen adjacent the side wall for preventing direct access of the dryingmedium to said wall adjacent the top of the chamber, an inlet for thedrying mediumto said supply chamber, a baflle for distributing thedrying medium in the supplychamber, and exhaust outlets at the bottom ofthe drying chamber.

5.v In an apparatus for drying latex, an enclosing wall having a closedtop, a well depending oentrally from said top, a disk spraying deviceextending through said well and closing the top thereof, the sprayingdisk being below the well, a screen extending from r a supply chamberfor a drying medium above Ill

